JPH11216561A - Metallic plate cutting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain generation of cutting failure at a gas cutting start position, reduce the down time of a coil checking facility, and improve rate of operation by setting a preheating time to the time equal to a factor proportional to the plate thickness of a cutting part. SOLUTION: Steel kind information, plate thickness information, plate width information, cutting start signals and the like are input to a controller 21. From a plate thickness measuring instrument 23, the plate thickness information t of the present coil is input, so as to obtain a preheating time T. T is designated by the function: T=K (see/mm) t (mm)+α (sec), and α is a coefficient decided by the distance and the like between a burner 12 and a cutting start point. K is also a coefficient, and is 1 in the case of a general steel. When the coil is rewound by a given volume and stopped, and the cutting start signal is input from the control part of the rewinding device, the controller 21 carries out preheating of the plate thickness direction end part being the cutting start point for the obtained preheating time. Thereafter, the moving commands of the volume corresponding to the plate width information are supplied to a carriage 20. Thus, the carriage 20 is moved in a plate width direction so as to carry out cutting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cutting a metal plate such as a coiled steel plate in a hot-rolling facility or the like, which is rewound and cut into predetermined length units by a gas burner.

[0002]

2. Description of the Related Art In a hot rolling facility, a part of a hot-rolled coil is transported to a coil inspection facility, and the coil is rewound off-line for inspection. By cutting, the defective shape portion is removed and the steel plate is sampled.

[0003] At the time of cutting by the gas burner, in consideration of the fact that the hot-rolled steel sheet is a thick plate, the end portion in the sheet width direction, which is the starting point of cutting, is preheated by the gas burner. Here, if gas cutting is performed without performing preheating, the plate edge (cutting start point) may not be cut as expected and a cutting failure may occur.

[0004]

However, in the prior art, target steel plates are classified into two types, thick materials and thin materials, and a fixed preheating time is set for each classification unit.

[0005] For this reason, when the range of the thickness of the steel sheet to be processed by the hot equipment is widened, the preheating time is insufficient due to the steel sheet, which may cause a cutting failure, or may cause unnecessarily heating, and the fuel consumption rate may be reduced. There is a problem that it gets worse.

[0006] The present invention focuses on the above-mentioned problems, and an object of the present invention is to prevent the occurrence of defective gas cutting.

[0007]

In order to solve the above-mentioned problems, a method for cutting a metal plate according to the present invention is to rewind a coil-shaped metal plate appropriately with a rewinding device and cut the metal plate with a gas burner. In this case, a method for cutting a metal plate that starts cutting after preheating a cutting start point for a predetermined preheating time, wherein the preheating time is set to a time equal to a function proportional to the thickness of the cut portion. It is assumed that.

According to the present invention, it is possible to surely perform appropriate preheating according to the thickness of a metal plate to be cut. here,
The present invention does not affect the sheet width because the problem of poor cutting at the cutting start portion in gas cutting is a problem.

[0009]

Next, embodiments of the present invention will be described with reference to the drawings. First, the equipment using the cutting method of the present invention and its operation will be described.
As shown in (1), a drawing path 1 (coil car rail) for drawing out the coil 5 from the hot rolling line L in an orthogonal direction is provided. Connected to the drawer path 1 and the coil inspection area 2
A transfer path 3 (rail for a coil car) is provided to this end. Reference numeral 4 indicates a rewinding device.

The coil 5 transported from the hot rolling line L to the coil inspection area 2 through the drawing path 1 and the transport path 3 is rotatably supported by a mandrel 6 of a rewinding device 4 as shown in FIG. You. Reference numeral 7 indicates a saddle of a coil car for transporting the coil 5.

Next, among the plurality of snubber rolls on the outer periphery of the coil 5, A, D and F are brought into contact with the outer periphery of the coil 5 to support the coil 5 as shown in FIG. . Further, the tip detection device 8 is pressed against the outer periphery of the coil 5. The tip detecting device 8 includes a pair of rolls 8a that come into contact with the coil 5 and a distance meter 8b that faces the outer peripheral surface of the coil 5 at a predetermined distance, and the coil is determined by a steep distance change based on a detection value of the distance meter 8b. 5 for detecting the tip 5a.

Next, when the coil 5 is rotated backward (counterclockwise) by a predetermined amount, the roll D is retracted and the peeler 9 is placed close to the coil 5 as shown in FIG. The peeler 9 is integrated with a sampling device described later. Therefore, a sampling device (not shown) is also in a state of approaching the coil 5.

Next, as shown in FIG.
Is installed, and the snubber rolls B, C, and D are made to approach a fixed position at a predetermined distance from the outer periphery of the coil 5. Next, as shown in FIG. 8, the coil 5 is unwound. Then, the tip of the coil 5 comes into contact with the peeler 9 and the tip detection plate 19,
Only the leading end of the first coil of the coil 5 floats as if it were peeled off. The floating amount is regulated by the snubber rolls B, C, and D.

Next, as shown in FIG.
Is raised once and then lowered as shown in FIG. 10, thereby guiding the steel sheet into the steel sheet guide path 11 of the sampling device 10 as shown in FIG.

Here, the sampling device 10 has a steel sheet guide path 11 extending in the vertical direction, a gas burner 12 is arranged above the steel sheet guide path 11, and a vertically movable fork 13 is arranged below the steel sheet guide path 11. Be composed. Below the steel sheet guide path 11, a crop bucket 14 is provided on the coil 5 side, and a sample bucket 15 is provided on a side apart from the coil 5 along with the crop bucket 14.

As shown in FIG. 12, the leading end of the coil that has entered the steel sheet guide path 11 is cut in the sheet width direction after the cutting start point (end in the sheet width direction) is preheated by the gas burner 12. You. The cutting will be described later. As shown in FIG. 13, the cut steel piece 16 at the leading end is lowered and rests on the receiving plate 13 a of the fork 13, and then the receiving plate 13 a descends and turns downward, so that the above-mentioned steel piece 16 becomes a crop bucket. It is dropped as a scrap into 14.

Subsequently, as shown in FIG. 14, when the coil 5 is further unwound and the leading end side of the coil 5 enters the steel sheet guide path 11 by a predetermined length, cutting is started by the gas burner 12 in the same manner as described above. After preheating the point, cut it. The cut steel piece 17 rests on the receiving plate 13a.

Subsequently, as shown in FIG. 15, after the sampling device 10 is retracted, the steel plate 17 (sampling) is dropped into the sample bucket 15 by lowering and rotating the receiving plate 13a downward.

With the above operation, the cutting of the tip of the coil 5 and the collection of the sample are completed. The coil 5 having undergone the inspection operation is transported to the next step by retreating all the snubber rolls, placing it on a coil car again.

The gas burner 12 is fixed to a carriage 20, as shown in FIG. Carriage 20
Are disposed so as to be able to run in the width direction of the steel plates 16 and 17 by themselves. The movement of the carriage 20 is operated by a command from the controller 21. Here, reference numeral 22 indicates a gas supply path for supplying LP gas to the gas burner 12. The symbol x indicates an end in the sheet width direction which is a cutting start point.

The controller 21 receives steel type information, sheet thickness information, sheet width information, a cutting start signal, and the like. That is, the current thickness information t of the coil 5 is input from the thickness measuring device 23 such as the distance meter 8b of the tip detecting device 8, and the preheating time T is obtained based on the following function.

T (second) = K (second / mm) · t (mm) + α (second) The above α is a coefficient, and is a unit heat quantity (obtained from a gas flow rate, a gas pressure, or the like) by the burner 12 or preheating. Burner 12
It is determined on the basis of the distance between the cutting start point and the like. Therefore,
Α is a constant if the gas flow rate, gas pressure, etc. are constant.

Similarly, the above K is also a coefficient and varies depending on the type of steel or the like. Then, when the coil 21 is rewound by a predetermined amount and stopped, and the cutting start signal is input from the control unit of the rewinding device, the controller 21
Preheating of the end in the sheet width direction, which is the cutting start point, is performed for the obtained preheating time T, and thereafter, a movement command of an amount corresponding to the sheet width information is supplied to the carriage 20. As a result, the carriage 20 moves in the plate width direction to perform cutting.

When the gas burner 12 moves by an amount corresponding to the sheet width information and the cutting is completed, a return command is supplied to the carriage 20 to cause the gas burner 12 to wait at the initial position. In the above-described gas cutting, an appropriate preheating time T is reliably set in accordance with the plate thickness t, and a cutting defect at the start of cutting can be suppressed.

Further, since preheating is not performed more than necessary, it leads to a reduction in processing time and a reduction in the amount of LP gas used.

[0026]

EXAMPLE In practice, LP gas was used as a fire source for a gas burner 12, the gas flow rate was 2 Nm ³ / Hv, and the pressure was 4
kg / cm ² , α is a constant value of “3”, K is “1”, and the thickness of the steel sheet is variously changed to carry out cutting work, and the occurrence of poor cutting at the end of the steel sheet (cutting start point) I tried to find the rate.

FIG. 2 shows the result. In FIG. 2, the circles are based on the invention of the present application. In addition, Δ marks are obtained as a comparative example when cutting is performed by preheating with two types of conventional preheating times of a thin material and a thick material.

As can be seen from FIG. 2, when the cutting method according to the present invention is employed, the defective cutting rate can be greatly reduced.

[0029]

As described above, when the present invention is employed, the occurrence of cutting failure at the gas cutting start position can be greatly suppressed, and the downtime of the coil inspection equipment is greatly reduced. Therefore, there is an effect that the facility operation rate can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of gas cutting according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a relationship between a plate thickness and a cutting failure occurrence rate.

FIG. 3 is a diagram illustrating a conveyance path of a coil.

FIG. 4 is a diagram illustrating the operation of the rewinding device.

FIG. 5 is a diagram illustrating the operation of the rewinding device.

FIG. 6 is a diagram illustrating the operation of the rewinding device.

FIG. 7 is a diagram illustrating the operation of the rewinding device.

FIG. 8 is a diagram illustrating the operation of the rewinding device.

FIG. 9 is a diagram illustrating the operation of the rewinding device.

FIG. 10 is a diagram illustrating the operation of the rewinding device.

FIG. 11 is a diagram illustrating the operation of the rewinding device.

FIG. 12 is a diagram illustrating the operation of the rewinding device.

FIG. 13 is a diagram illustrating the operation of the rewinding device.

FIG. 14 is a diagram illustrating the operation of the rewinding device.

FIG. 15 is a diagram illustrating the operation of the rewinding device.

[Explanation of symbols]

 4 Rewinding device 5 Coil 12 Gas burner 20 Carriage 21 Controller

Claims (1)

[Claims] 1. A coil-shaped metal plate is appropriately wound by a rewinding device.
A method for cutting a metal sheet, in which when the metal sheet is rewound and cut by a gas burner, cutting is started after preheating a cutting start point for a predetermined preheating time, wherein the preheating time is proportional to the thickness of the cut portion. A method for cutting a metal plate, wherein the time is set to be equal to the set function.